


Mercy

by Ninni



Category: Supernatural
Genre: Anal Fingering, Anal Sex, Demon!Dean, Dity talk, Hurt No Comfort, Hurt!Sam, M/M, Rape, Rough Oral Sex, Wincest - Freeform, dubcon, noncon
Language: English
Status: Completed
Published: 2017-08-16
Updated: 2017-08-16
Packaged: 2018-12-16 06:26:33
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,650
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11823078
Author URL: https://archiveofourown.org/users/Ninni/pseuds/Ninni
Summary: Dean is done denying himself what he wants. Demon!DeanxSam.





	Mercy

”And what I’m gonna do to you, Sammy – well. That ain’t gonna be mercy either.”

Sam caught a glimpse of his brother’s unsettling grin in the rearview mirror. Dean’s teeth gleamed in the faint light from the streetlamps. His eyes were fixed on the back of Sam’s neck, unblinking. The creature in the backseat of the Impala truly was a demon, but Sam knew – he fucking knew – that his brother was still in there.

Dean was still within Sam’s reach.

His voice was quiet when he spoke. “I’ll have you back, Dean. I’ll take you back, you hear me?”

Dean’s laugh was soft and cruel, crackling with promise. Sam tried to ignore the chill that ran down his spine.

“This demon thing sure as hell is interesting,” Dean drawled in that impossibly rough voice of his.

Sam stopped, turning around to face his demonic brother who was currently tied to a chair, a devil’s trap keeping him there. Sam swallowed before he took the bait. “Why?” he asked, shortly.

“It changed me, Sammy. And I’m not just talking about my pretty black pebbles.”

Dean’s black eyes turned green and glittering as his mouth twisted into a smirk. “I used to hate weakness,” he said. “Weakness in others. In you,” he said, grinning as Sam twitched. “It made my skin crawl. I didn’t know what to do with all that weakness. Didn’t know how to make it go away. Now, though. Now I see it in a whole new light.”

Sam felt nausea twist his gut as Dean’s eyes stared intently at him, the tip of his pink tongue grazing his bottom lip. “How?” he asked, tonelessly.

Dean threw his head back and laughed. “Now I fucking love it!” he growled, his chest heaving. “My god, Sammy – I can smell that weakness in you. All that fear. Smells so fucking good.”

Sam swallowed as he reflexively took a step back. “I’m not afraid of you,” he said, and he could tell from Dean’s feral grin that he knew as well as Sam did that he was lying through his teeth.

Dean was a crazy, newborn demon running on raw power and rage. Sam was a human with a useless arm. He was absolutely terrified.

“You know it’s only a matter of time before I get out of this chair, Sam. Do you have any idea what I’m gonna do to you when I do?”

Dean’s green eyes met his. There was an unnatural coldness in them; a deep and menacing promise in the gaze that Dean really, really didn’t plan on showing Sam any mercy.

Sam looked away and began walking towards the door. He needed to get out of there, he felt cold and almost shivery and he’d be damned if he let Dean see the impact he was having. Over his shoulder, Sam replied: “I’m gonna have to keep you in that chair, then.”

*

The empty chair that met Sam when he returned a few hours later sent a cold, foreboding chill down his spine. Taking a deep breath to keep himself from panicking, he did his outmost to keep his head cold, however that was the moment when a firm hand wrapped around his throat and tugged him backwards, causing him to fall to the ground on his knees.

“I told you,” Dean growled against his ear. “Only a matter of time, Sammy.”

Dean gripped Sam’s damaged arm with a dark chuckle, squeezed it, and when Sam passed out, he didn’t know it was from the shock or the pain.

*

When Sam woke up, he couldn’t move. He was tied to his bed, except for his useless arm, which rested painfully over his chest. When he realized that he was naked he felt a kind of panic he’d never experienced before surge through him, it made his skin crawl, and he had to stifle his first impulse, which was to cry out to Dean for help.

Turned out, Dean was already there. He sat in a chair in the corner, watching Sam. His eyes were completely black, and Sam fought back tears.

“Dean,” Sam said, his voice pitiful and pleading even to his own ears. “Please, I know you. I know you’re still in there.”

Dean got up from the chair, his eyes shifting back into his green, the familiarity of them a taunt.

“There was enough humanity in me to be able to walk right past that devil’s trap,” Dean murmured, eyes roaming in an unsettling way over Sam’s naked body. “And I’m finally gonna do to you what Dean was too much of a pussy to do when he was human.”

Sam’s gut twisted as he saw the twinkle in Dean’s eyes. “What the hell are you talking about?” Sam asked, tugging desperately at his restraints.

Dean licked his lips as he shrugged out of his shirt. “You gotta be blind, Sammy. Did you never connect the dots? Why the fuck did you think Dean was so obsessed with you? Huh? The way you broke his heart when you left to be some beer chugging frat boy; how he died for you, how he tied himself to you in every possible way? Did you think that was all out of good old fashioned brotherly affection? Were you really that naive, Sammy?” 

Sam watched in horror as Dean shed his jeans, still with that predatory gleam in his eyes. “You’re lying,” he said vehemently. “Demons always lie.”

Dean smirked. “Human enough to feel what Dean wants, baby brother. And enough demon in me to give him exactly that.”

Sam made a noise of protest as Dean straddled him with a moan, rubbing his dick against Sam’s belly. “Fuck, how long I’ve wanted this,” Dean sighed. “You have no idea, little brother. Been thinking about pounding that sweet little ass of yours since you were fifteen.”

Sam twisted beneath him, a pathetic mewl of objection escaping him before Dean backhanded him, hard, across his face. “I know you fucking want this too,” Dean growled above him, stroking his hard cock with leisure.

“No, I don’t!” Sam gasped, squirming furiously beneath Dean, his heart hammering with panic in his chest, his cheek burning from the blow.

“I don’t care,” Dean hissed against his ear, his fingernails scraping against Sam’s nipples. “You’ll pretend you want it, you hear me? I want to hear you beg for my cock, Sammy.”

“Please,” Sam begged, muffled into Dean’s warm neck. It smelled of his brother, it smelled like safety, and he couldn’t seem to stop the tears. “Please Dean, don’t do this.”

Dean moved up, his knees digging into Sam’s ribs. His teeth gleamed when he ordered, breathlessly: “Open your mouth. You’re gonna look so good with your lips wrapped around my cock.”

Dean’s leaking cock rubbed against Sam’s lips, coating them with precum. Sam closed his eyes, repressed a sob, and opened his mouth. Dean’s cock was heavy and bitter on his tongue and Sam tried not to choke on it when the tip hit the back of his throat.

“Shit,” Dean gasped, eyes half lidded as they looked down at Sam in awe, his fingers grasping Sam’s hair as he fucked his mouth. “You were made for this, Sammy. Should’ve done this years ago.”

Sam was a gasping, spluttering mess when Dean pulled out, his voice raspy and broken when he begged: “Stop it, Dean please stop it, I can’t do this.”

Dean dragged his thumb over Sam’s cheekbone, mockingly wiping away his tears. “Yes you can, Sammy. Doing beautifully.” Dean held up two fingers at Sam’s abused mouth, his other hand still wrapped up in Sam’s hair, keeping his head in place. “Get them nice and wet, baby boy, cause this is all prep you’re getting.”

Sam stared up at Dean, his entire body going stiff with anxiety. He shook his head. “No. No, Dean, not this. Don’t do this to me, to us.” 

Dean grinned against Sam’s cheek, inhaling deeply, forcing his fingers into Sam’s mouth. “You’ve no idea how many times I’ve thought about this. How fucking guilty I’ve felt all these years for wanting to bend my little brother over and make you take it for me, to own you; to mark you up. Fuck, Sam. Your Dean is in here, you get that? He’s right here, and you know what? He loves this.”

Dean’s eyes were black again, and Sam whined around the fingers in his mouth, head reeling. Soon, Dean withdrew his fingers and began to push at Sam’s reluctant entrance, smearing spit across the furled muscle.

“Relax that pretty hole for me sweetheart,” Dean whispered against Sam’s ear, making Sam shudder.

“Fuck you,” Sam spat, arching his body as much as he can to get away, crying out when Dean bit into his throat.

“I’m gonna fuck that spite right outta you,” Dean promised in a dark whisper as his fingers pushed into Sam’s reluctant body. “Gonna make you beg for it, Sammy. Always wanted to hear you moan for my cock.”

Sam hissed as Dean’s fingers proceeded to move, scissoring him open deliberately. Sam wished it had hurt, wished he had sharp pain to focus on, but Dean went so slowly and methodically that he only felt a slight burn where he was being stretched open. “Dean,” he whispered again, even if he began to realize that it was useless. “Don’t, please.”

Dean’s black eyes stared down at Sam’s face, transfixed, as he began to fuck Sam with his fingers. “So hot and sweet in here, brother,” Dean said hoarsely. “Always knew you’d be.”

Dean did something then, crooked his fingers, and touched something inside Sam that sent a jolt of pleasure through him and pulled an unexpected, unwanted moan from him. Dean laugh was soft and triumphant. “Like that, baby?”

Sam shook his head furiously, feeling his face heat up with shame as he felt his cock rise against his will, curling up against his stomach, flushed and leaking. “No!” he lied, squeezing his eyes shut.

“Now who’s the liar,” Dean murmured, pressing against that spot again, making Sam arch his back from the pleasure, biting his lip to keep from moaning. “Let go, little brother. I want you to want this.”

The third time Dean’s fingers assaulted that little bundle of nerves that seemed to set Sam on fire, he couldn’t help himself. He pushed against Dean’s fingers, into the touch, and whined from the overwhelming sensation that washed over him. Sam turned his face away from Dean’s, humiliated.

“You look so hot like this,” Dean purred against the shell of his ear, his fingers lazily fucking in and out of Sam’s body. “You want more, don’t you? You want my cock, right? Tell me you want my cock, Sammy. Beg for big brother.”

“You’re not my brother,” Sam hissed into the room, still refusing to face Dean. He couldn’t bear those ugly black eyes jammed into Dean’s wonderful face; couldn’t bear the shame of being so utterly betrayed by his body that he actually was beginning to enjoy this awful, nightmarish creature’s treatment.

“Yes I am,” Dean growled, impatience vibrating through every word, making Sam tremble. “I’m your brother, and I will fuck you, because I’m finally taking what I’ve been denying myself for years. Now, can I untie your legs? Will you be a good boy for big brother, Sammy?”

Sam turned his face towards Dean in a flash of anger and spat him right in one of those horrible eyes. Dean immediately rewarded him with another harsh blow across his face, and this time, Sam could taste blood in his mouth.

Dean’s mouth curled into a cruel sneer. “I want you to enjoy this,” he snarled, “That doesn’t mean I won’t go through with it even if you don’t. Now, I’m asking again: Can I untie your legs, or do you want to get fucked all tied up like the little bitch you are?”

Sam swallowed both blood and his pride. “You can untie me.”

When Sam’s legs were free, he made some futile attempts to kick at Dean, who easily caught his legs and wrapped them around his waist. He smirked down at Sam, reaching out to stroke Sam’s now half hard cock back to full erection, and said: “This is where you’ve always belonged, Sammy. You’ll see.”

He lined himself up against Sam’s loosened opening, and pushed all the way in, causing Sam to cry out in pain. “Dean, it hurts!” It came out on impulse, because Dean had always been the one to fix things, to take care of him when he was in pain.

He certainly wasn’t now.

Dean began to move, his thrusts hard and merciless. “Oh god, fuck, yes, that’s – ah, Sam, you’re so fucking tight, so hot, fuck-“

Sam squeezed his eyes shut, refusing to let that black stare etch itself into his memory more than it already had. Then Dean changed his angle ever so slightly, and he began to hit that one spot that had made Sam see stars.

Sam thrashed under him, involuntary wrapping his legs firmer around Dean, as little ah!ah!ah’s unbiddenly began to pour from his lips. Dean lowered himself to they lay flush against each other, Dean’s stomach rubbing against Sam’s leaking cock with every thrust.

Dean’s voice brimmed with awe when he gasped into Sam’s neck: “You feel that, Sammy? Feel how good we are together?”

Sam made a feeble noise, too lost in the assaulting pleasure to care that he couldn’t form a coherent protest. Dean slowed down the pace of his thrusts, holding Sam’s leg up to ensure that he still hit that sweet spot over and over again. Sam could only make undignified, keening noises as Dean fucked him every so slowly towards the edge.

Dean’s voice was almost unbearably soft when he said: “Look at me, Sam.”

Dean’s green eyes were back, so warm and familiar that Sam almost for a second believed this was his Dean, and he sobbed softly, “Dean.”

Dean cupped his face gently and pressed his lips against Sam’s, drinking down Sam’s moans. He kissed him softly, teeth only grazing over Sam’s bottom lip. “Come for me,” Den whispered against his lips, fingers curling gently around Sam’s throat. “Sammy, please?”

Sam came with a soft whimper, his face wet with sweat and tears. He felt Dean follow almost immediately, shooting his hot load inside Sam’s body with a throaty grunt, before he collapsed on top of him.

“Please get away from me,” Sam said, trying his outmost to find dignity and strength within himself to not sound completely broken. He could tell that he failed completely, because Dean looked at him in pity.

Dean’s rough voice was matter-of-factly when he told him: “You liked it, Sammy. I could tell. You wanted it.”

Sam curled up, wishing for anything to cover himself up with. He felt the demon’s come leak out from him, and he buried his face in the pillow. 

“I wanted it with Dean,” Sam confessed tonelessly into the room. “I’ve known for years that what I want from him is something far more than simply being brothers. I never found the courage to tell him, and now – everything’s ruined. You’ve taken everything from me, from us. What could’ve been. It’s gone now.”

Dean, or the demon, or whoever it was who lay beside Sam stared at him under silence; unsure green eyes flickering over Sam’s face as if trying to find proof that he’s lying.

Sam closed his eyes, and when he opened them he was beneath a blanket. The restraints were gone, and so was Dean. Castiel sat next to him on the bed, looking more morose than usual.

Castiel told him that Dean was cured; that he’d only been one shot of human blood away from humanity.

Sam didn’t answer.


End file.
